• ETRI Journal
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• 제33권3호
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• pp.443-453
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• 2011

This paper evaluates the efficiency of mobile content firms through a hybrid approach combining data envelopment analysis (DEA) to analyze the relative efficiency and performance of firms and principal component analysis (PCA) to analyze data structures. We performed a DEA using the total amount of assets, operating costs, employees, and years in business as inputs, and revenue as output. We calculated fifteen combinations of DEA efficiency in the mobile content firms. We performed a PCA on the results of the fifteen DEA models, dividing the mobile content firms into those having either 'asset-oriented' or 'manpower and experience-oriented' efficiency. Discriminant analysis was used to validate the relationship between the efficiency models and mobile content types. This paper contributes toward the construction of a framework that combines the DEA and PCA approaches in mobile content firms for use in comprehensive measurements. Such a framework has the potential to present major factors of efficiency for sustainable management in mobile content firms and to aid in planning mobile content industry policies.

• International journal of advanced smart convergence
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• 제9권4호
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• pp.52-61
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• 2020

The AHP method was used in 30 provinces of China to construct the index system of creative space efficiency evaluation and determine the weight of each index. The fuzzy comprehensive evaluation method was further used to score the indexes at all levels, and then the total efficiency score was sorted. The purpose of this study is to adjust the regional layout of creative space reasonably and implement financial policies accurately through the evaluation of the efficiency of creative space. The results is ranking top in weight of several indicators, which include the number of incubated Startups, the number of innovation and entrepreneurship mentors, the survival rate of incubator, the innovative training activities, etc. It was also found that Beijing, Shanghai, Jiangsu, Guangdong and Zhejiang ranked first in the score of creative space efficiency. This study is meaningful in that it was In order to effectively solve the problem of the imbalance of the creative space efficiency in China's province, by coordinating the regional pattern, establishing a sound service system and improving the efficiency evaluation system.

• 보건행정학회지
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• 제4권2호
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• pp.77-110
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• 1994

This study is an empiriacl analysis of effects of government intervention on the health care delivery system in Korea. The purposes of this study are to find out the effects of government intervention on the per capita national health expenditure(per capita NHE), crude mortality rate(CMR), and institutional efficiency. Here, the institutional efficiency is defined as a formula shown below: log$\frac{100-curde mortality rate }{per capita NHE}$$\times$100. The formula indicates that the instiutional efficiency increases if the CMR and/or per capita NHE goes down. In the meantime the government intervention is measured by six independent variables: I) the degree of social developments, ii) the numberr of physicians per 100, 000 population, iii) the proportion of specialists among the total physicians, iv) the proportion of public expenditure among the NHE, v) the proportion of public beds to the total number of beds, vi) the proportion of physicians working at the public sector to the total number of physicians. In the above six independent variables iv), v) and vi) are the ones that reflect the degree of government intervention. In actual calculation, the two independent variables v) and vi) are integrated into a new variable based on one to one correspondence. The materials used are the time-series data from 1970 through 1990 in Korea. A path analysis and the time-series regression analysis were adopted to estimate and examine the causal relationship between variables involved. And decomposition of the effect of causal relationship is made to find net effect, direct and indirect effect. The major findings are as follows; 1. The effect of public expenditure, number of physicians per 100, 000 population, the proportion of specialists among the total physicians and social development shows a positive relationship with per capita NHE. Only if the government intervention would be counted, the effects of the number of physicians and the proportion of specialists succeed in containing per capita NHE. 2. In additionn to the above four variables, one additional variable, per capita NHE, was also responsible for the reduction of CMR. The factor of social development found to be the most potent predictor of the CMR reduction. However, the CMR reduction due to government intervention was negligible. 3. Meanwhile, the above four variables were found to was have negative effects on the institutional efficiency. The reverse is true when the government intervention is counted. For example, the number of physicians and the proportion of specialists have played a positive role in raising institutional efficiency via goverment intervention. This comes from the factual effect that the increment of institutional efficiency via the reduction of per capita NHE is bigger than via the reduction of CMR.

• 한국습지학회지
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• 제20권4호
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• pp.417-423
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• 2018

축산 지역 하류에 위치한 농업용 저수지의 강우시 유입, 유출수 분석을 통해 축산지역의 강우 유출 특성과 저류지에 의한 축산계 비점 오염물질의 저류형 시설에 의한 유출 저감 효율을 분석하였다. 급경사지에 위치한 한우 축산 지역의 비점 오염물질 유출은 주로 초기세척현상에 의해 발생됨을 알 수 있었으며 강우시의 유입수 농도는 비강우시에 비해 SS농도가 가장 높게 발생하고 있으며 T-P도 4배 이상 증가하는 양상을 보인다. 반면 총질소는 평균 30% 증가하는 것으로 나타나는데 질소항목으로 보면 질산성 질소는 거의 변화가 없는 반면에 암모니아성 질소가 2배 이상 증가하고 있다. 저류형 비점 제거시설 효율 분석 결과 비강우시 총인 제거효율이 53%로 가장 높고 부유물질은 37% 제거되고 있다. 유기물질은 10% 내외, 총질소는 5% 이내로 제거되며 부영양화로 녹조가 번성하는 하절기에는 오히려 유출수의 질소농도가 더 높아지는 경우도 빈번히 발생하고 있다. 강우시의 유입수 농도는 비강우시에 비해 SS농도가 가장 높게 발생하고 있으며 T-P도 4배 이상 증가하는 양상을 보인다. 강우시 부유물질의 제거효율은 60%로 나타나고 있으며 총인은 22% 제거되어 비강우시에 비해 제거효율은 감소하고 있다. 환경부의 비점제거시설 기준보다 9배 이상의 용량을 지니고 있지만 비점 전용 시설로 활용되지 못하는 탓에 장마철에 거의 만수 상태로 담수하여 비점제거 효율에 있어서는 충분한 효과를 보이지 못하고 있는 것으로 나타나 저수지의 용량 뿐 아니라 수문관리 등 유지관리도 비점 제거효율에 영향을 미치는 중요 인자로 분석되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.580-585
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• 2012

R744용 해양온도차 발전 시스템의 작동변수에 대한 기초 설계자료를 제공하고자 증발열량, 응축열량, 전체일량, 효율에 대한 사이클 성능을 분석하였다. 본 연구에서 고려된 작동변수는 R744 해양온도차 발전 사이클의 과열도, 과냉각도, 응축온도, 증발온도 등이다. 주요 결과를 요약하면 다음과 같다. R744의 증발열량은 과열도와 과냉각도가 증가할수록 증가하는 반면, 응축온도가 증가할수록 감소한다. 전체일량은 R744의 과열도와 과냉각도와 함께 증가하나 증발온도는 증가할수록 감소한다. 그리고 효율은 과열도와 과냉각도가 증가할수록 증가하는 반면, 응축온도는 감소한다. 그러므로 R744용 해양온도차 발전 시스템의 증발열량, 응축열량, 전체일량, 효율은 과열도, 과냉각도, 응축온도, 증발온도, 펌프와 터빈 효율에 영향을 받는 것을 알 수 있었다. 따라서 R744용 해양온도차 발전 시스템의 설계시에는 이러한 영향을 면밀하게 파악하여야 한다.

• 수산해양기술연구
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• 제47권4호
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• pp.290-299
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• 2011

Field tests were carried out with five different mesh sizes (86.6, 101.0, 121.2, 137.7, 151.5mm) to study the relative efficiency of monofilament and multifilament gill net for Marbled sole, Pleuronectes yokohamae, in the western sea of Korea, 2007-2009. The relative efficiency was analyzed by length distribution, catch in number, catch in weight and weight per individual for Marbled sole. Statistical T-test was done to verify the efficiency between two gears. In the field tests, the total body length range, catch in number and weight of Marbled sole was 15.8-48.2cm, 728 and 254,939g, respectively. During the field tests, Marbled sole less than 15cm length which is prohibition size of fishing was not caught, but the caught number of Marbled sole less than 19.5cm length which is first maturity length was 13 (1.8%) and the caught number of Marbled sole more than 19.5cm was 715 (98.2%). Catches of monofilament gill net was average 1.4 times more efficient than multifilament gill net. The weight per individual and total length by mesh sizes in the two gears tended to gradually increase according to mesh size increasing. But there was little difference of weight per individual and total length by mesh sizes between two gears.

• 한국환경과학회지
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• 제10권1호
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• pp.59-64
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• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

• 한국수소및신에너지학회논문집
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• 제25권1호
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• pp.87-96
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• 2014

Direct combustion characteristics of coal and oxygen carrier were measured in the thermogravimetric analyzer using four coals and two different oxygen carriers. The direct combustion efficiency decreased in order of Roto, Kideco, Sunhwa and Hyper coal for both oxygen carriers. Moreover, OCN703-1100 oxygen carrier showed better combustion efficiency than OCN706-1100 oxygen carrier for all four coals. The reduction characteristics of two oxygen carriers for $CH_4$, CO and $H_2$ gases were measured in the thermogravimetric analyzer to investigate why OCN703-1100 oxygen carrier showed better combustion efficiency than OCN706-1100 for all coals. The OCN703-1100 oxygen carrier represented higher reduction rate than OCN706-1100 for all reducing gases. Moreover, the total pore area and the porosity of OCN703-1100 were higher than those of OCN706-1100 oxygen carrier. The total volatile gas and volatile components of four coals were measured in a batch type fluidized bed reactor to investigate why the direct combustion efficiency decreased in order of Roto, Kideco, Sunhwa and Hyper coal for both oxygen carriers. The direct combustion efficiency was proportional to the total amount of ($CH_4+CO+H_2$) produced during devolatilization of coals.

• 에너지공학
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• 제16권4호
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• pp.164-169
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• 2007

우리나라에서 여름철 피크전력부하의 감소는 매우 중요하다. 정부는 피크전력부하를 저감하기 위하여 많은 지원 정책과 법률을 제정하여 시행하고 있다. 그리고 빙축열시스템은 이런 대안 중의 하나로서 알려지고 있다. 이 논문의 목적은 축열운전, 병렬운전과 축열조 단독운전이 수행된 밀폐식 빙축열시스템의 축열조 성능과 전체 효율을 평가하는 것이다. 설계조건에서 운전된 빙축열시스템의 자료를 이용하여 축열조의 축열밀도와 방냉효율 그리고 시스템의 총괄에너지 이용효율을 계산하면 $18.4\;USRT-h/m^3$, 96.2% 그리고 2028.7 kcal/kWh이다. 빙축열시스템의 축열조에 공급되는 에너지를 설계조건보다 많게 공급하면 과냉각효과에 의해 설계조건보다 시스템 효율이 낮게 평가되어진다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권4호
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• pp.548-555
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• 2019

Objective: The main objective of this study was to evaluate the effect of different feeding levels of a total mixed ration silage-based diet on feed intake, total tract digestion, enteric methane emissions, and energy partitioning in two beef cattle genotypes. Methods: Six mature bulls (three Thai natives, and three Thai natives - Charolais crossbreeds) were assigned in a replicated $3{\times}3$ Latin square design, with cattle breed genotype in separate squares, three periods of 21 days, and three energy feeding above maintenance levels (1.1, 1.5, and 2.0 MEm, where MEm is metabolizable energy requirement for maintenance). Bulls were placed in a metabolic cage equipped with a ventilated head box respiration system to evaluate digestibility, record respiration gases, and determine energy balance. Results: Increasing the feeding level had no significant effect on digestibility but drastically reduced the enteric methane emission rate (p<0.05). Increasing the feeding level also significantly increased the energy retention and utilization efficiency (p<0.01). The Thai native cattle had greater enteric methane emission rate, digestibility, and energy utilization efficiency than the Charolais crossbred cattle (p<0.05). The daily metabolizable energy requirement for maintenance in Thai native cattle ($388kJ/kg\;BW^{0.75}$, where $BW^{0.75}$ is metabolic body weight) was 15% less than that in Charolais crossbred cattle ($444kJ/kg\;BW^{0.75}$). Conclusion: Our results suggested that the greater feeding level in zebu beef cattle fed above maintenance levels resulted in improved energy retention and utilization efficiency because of the reduction in enteric methane energy loss. The results also indicated higher efficiency of metabolisable energy utilization for growth and a lower energy requirement for maintenance in Bos indicus than in Bos taurus.